Finally, changing the angle of a ramp at which the car sets off from will alter the stopping distance because the higher the ramp the more gravity is acting on the car to pull it down therefore increasing the speed and lengthening the stopping distance. This can be measured by the gradient of the ramp.
I am going to change the length of the ramp in order to measure and observe the stopping distance of the car. I will investigate how this effects the distance in which the car stops. When I change the length of the ramp I think that what will happen to the stopping distance is that it will increase. I will measure how high the car is on the ramp from the front of the car to see how far it goes.
The car will set off from a height giving it potential gravitational energy. As it travels down the ramp it continually accelerates in speed until it reaches the end of the ramp where the ground levels and the car now has no acceleration because the gravitational energy has been transferred into kinetic energy. The car now de-accelerates because of unbalanced forces acting on it. There is now larger counters force (factors such as friction and air resistance) on the car than a driving force. The energy is then transferred to heat and sound. A table to show the Length of the ramp against the height at which it is off the ground.
Fair Test
To keep the test fair I will keep the speed of the car the same, the type of car the same, the amount of air resistance and the surface/friction the same. This is so that we are only investigating the length of the ramp and the results will not be altered by any of the other variables.
Method
After setting up apparatus as shown in the diagram, hold the car 10cm up the ramp. Drop the car getting it to go in a straight a line. This so that the results are fair. Once the car has stopped measure the distance from the base of the ramp and repeat two times. After 3 tries at each height move the ramp up 10cm.
Diagram
Apparatus
Results
Analysis and Conclusion
My results show that I was correct with my prediction, in that the greater the height the longer the stopping distance. This is shown in the graph. It is a straight line graph and is proportional to 1:5 as shown. The results were reliable as they are similar when repeated. I have no anomalous results. This is because I repeated any results that didn’t fit the general pattern. In conclusion, the experiment has proven that when increasing gravitational potential energy you also increase the stopping distance of a car. This is due to the car being pull towards the earth, causing it to accelerate. This potential energy changes to kinetic, heat and sound energy as the car moves. The car has a bigger driving force than the counter forces acting on it. We know this as it move along the flat surface until all energy is transferred. This causes the car to slow and finally stop, there is no more driving force and the counter forces are balanced. This means the car is still.
To calculate how much gravitational potential energy the car has at each height I will use the equation Potential Energy = mass x g x height.
PE = mgh
m x g = weight of car = 31.2
This shows that with more height a car will go faster because it has more energy. At a faster speed it takes longer to stop.
If the amount of gravitational energy equals the amount of Kinetic energy.
PE = KE = ½ mv²
This table shows the results of the velocity at which the car is traveling at points down the ramp. The car accelerates and increases speed down the ramp as it gains more kinetic energy. This is shown in the graph. The line of best fit starts as a curve but increases as a straight line and at a proportional rate. The maximum speed of the car was 11cm per second and this was at the bottom of the ramp before it began to decrease in speed.
Evaluation
Overall the experiment went well will few problems. In each attempt I kept all variables the same to make it fair as explained before. Although, problems that I did encounter were that it was very hard to keep the car straight once released. Sometimes it would hit the side of the runway against a ruler which would have altered the results because any turning etc. would have slowed the car down. In order to improve this I would suggest having more time to make sure each attempt does not hit the side but goes in a straight line. Measurements could have been made more accurately by perhaps using another straight line (a ruler) from the car to the ruler so as to make sure it is inline, also, more accurate results could have been obtained by recording more decimals in the readings. All the results fitted with what I expected and fit with the general pattern. The readings are reliable enough to be sure about my conclusion as we repeated all results for confirmation.
